Conventional toy coin banks do not automatically recognize coin denomination. U.S. Pat. No. 4,673,368 of Vincent N. Bush, in view of this, discloses a toy bank with a novel coin discriminating mechanism. Bush has given a detailed description on conventional toy coin banks in "The Background of the Invention" of his specification and he discloses a new toy bank capable of detecting automatically the denomination of the inserted coins.
Bush's disclosure has taken U.S. coins, e.g. penny and dime which are only 1.1 mm different in diameters, as his sample coins, however, chances are that there is a great difficulty in measuring precisely such a micro difference in diameters as menitoned above. As everyone knows, it is not unusual to make errors in the production line and assembly line of the mechanism parts. Concerning to the structure of the discriminating mechanism in Bush's disclosure, such possible errors may easily cause an error in the discrimination for coins with micro differences in diameters. Though Bush did provide a certain mechanism to detect coins of various diameters, and even if the errors made can be adjusted and the mechanism parts can be reassembled, it is obvious that, a considerable cost for quality control of such mechnism as well as the extra cost for reassembly in the production line will be unavoidable.